End closure for container



March 12, 1957 l. L. WILCOX END CLOSURE FOR CONTAINER Filed Nov. 6, 1952INVENTOR. L. Wu. :0 X

w ggw v United States Patent END CLOSURE FOR CONTAINER Isaac L. Wilcox,Fulton, N. Y., assignor to Oswego Falls Corporation, Fulton, N. Y., acorporation of New York Application November 6, 1952, Serial No. 319,037

3 Claims. (Cl. 229-43) This invention relates to containers formed offibrous sheet material, such as paperboard, and has particular referenceto a novel end closure structure for such containers.

The primary object of the invention is to provide a container endclosure structure which may be formed quickly and economically, andwhich is particularly strong and leak-proof.

A further important object of the invention is to provide a containerend closure structure which forms an insulated bottom for the container,making it particuiarly useful for hot beverages.

The invention consists in the novel features and in the combinations andconstructions hereinafter set forth and claimed.

In describing this invention, reference is had to the accompanyingdrawings in which like characters designate corresponding parts in allthe views.

Figure 1 is a perspective view of a container embodying the end closureof the invention.

Figure 2 is a cross section through the container taken along line 2-2of Figure 1.

Figure 3 is a vertical section taken along line 3-3 of Figure 2,illustrating the details of the end closure structure.

Figure 4 is an enlarged section taken through the inner end closuremember.

The body of the container is of tubular formation, substantially squarein cross section, and may be provided with a yieldable top'flange ofconventional design for the reception of a slip cover 12, as shown. Thebottom closure structure, indicated generally at 14, comprises an innerend closure member 16 and an outer end closure member 18. The innerclosure member 16 is a substantially square blank, the peripheralmarginal portion of which is folded upon itself to form an inwardlyextending flange 20 in contact with the outer or bottom surface of theblank. In its folded form, member 16 is so dimensioned as to slidablyfit within the container body 10 and is positioned horizontally therein,with the outer surface of the flange 20 being coplanar with the edges ofthe container end, as shown in Figure 3.

The outer end closure member 18 is also formed from a substantiallysquare blank, the latter being of greater area than the cross sectionalarea of the container body 19. This blank is positioned in contact withthe outer surface of flange 20 and the edges of the container end sothat its center is in registry with the longitudinal axis of thecontainer body. The extending marginal portions of the blank are foldedupwardly into engagement with the outer walls of the end portion of thecontainer body forming an external flange or rim 22 surrounding thebody. The inner surface of member 18 is coated with impervious adhesivematerial which is preferably of the heat sealing type, such as Vinylite,or, if desired, both inner and outer end closure members 16 and 18, andthe end portion of container body 10 may be so coated. This coatingpermits the engaging surfaces of the flange 20 and member 18 to besealed together as at 24, and the engaging surfaces of the member 18 andcontainer body end portion to be sealed together as at 26, therebyforming a strong, liquid-tight end closure.

In assembling a large number of such end closures, a container body 10is usually mounted upon a movable mandrel and conveyed to a stationwhere an inner end closure member 16 is positioned in the containeragainst the end of the mandrel, the flange 20 having been previouslyformed on the member. The body 10 and end closure member are then movedinto registry with a supply of outer end closure blanks, and one ofthese is positioned against the flange 20 and edges of the container endand its extending marginal portion folded into engagement with the wallsof the container body to form the member 18. Thereafter, seals 24 and 26are completed upon the application of heat and pressure to the outersurface of member 18.

The end closure suucture described provides an insulated liquid-tightcontainer bottom, the insulating feature thereof being obtained by thedead. air space 28 in the enclosed, sealed chamber formed by the flange20 and inner and outer end closure members 16 and 18. In addition, itwill be noted that no uncoated or raw edges of the fibrous materialcomprising the container are in a position to contact a liquid containedtherein. Ordinarily, the sheets of fibrous material from which thecontainers are made are coated on both surfaces with a protectivemoisture resistant substance. However, when the individual containerelements, as for example the inner and outer end closure members 16 and18, are stamped or cut from a large sheet, the edges of the elements areuncoated, or in a raw state. Obviously, if the edges were in contactwith the liquid in the container, the liquid would soon be absorbedtherethrough and diminish the utility of the container. In theillusstrated construction, the seal 24 between the flange 20 and innersurface of member 18 prevents any liquid from coming into contact withthe uncoated peripheral edges of the inner end closure member 16. Itwill also be observed that the construction of the invention provides adouble liquid-tight seal, that is, seals 24 and 26, so that if liquid inthe container should happen to leak through the seal 24, due to somedefect therein, it would still have to work its way up through seal 28to escape from the bottom of the container.

From the foregoing description, it will be apparent that the inventionprovides a novel container end closure structure which may be quicklyand economically formed and which is particularly strong and leak-proof.In addition, the end closure structure provides an insulated bottomarrangement for the container so that the latter is particularly wellsuited for hot beverages.

What I claim is:

1. An end closure for a container having a substantially tubularcontainer body comprising an inner end closure member positioned in saidbody adjacent one end thereof, the marginal portion of said closuremember being folded upon itself to form an inwardly extending flangecontacting the bottom surface thereof, an outer end closure memberpositioned against said flange, the marginal portion of said outerclosure member being folded to engage the outer surface of the endportion of said container body, and means to seal said outer closuremember to said flange and container body in liquid-tight relation.

2. An end closure for a tubular container of substantially squarecross-section comprising a substantially square inner end closure memberhaving its marginal portion folded upon itself to form an inwardlyextending flange, said folded end closure being dimensioned to slidablyfit within said container and being positioned therein "with its flangecoplanar with one end thereof, a substantially square outer end closuremember positioned against said flange and the edge of said containerend, said 'outer closure member "being of greater area than thecross-sectional area of said container and having -'its extendingmarginal portion folded to engage the outer surfaces of the containerwalls adjacent said container end, and means on said outer end closureto seal 'it to said flange and "container walls upon the application ofheat and pressure.

3. An end closure as defined in claim 2, wherein said flange and innerand outer end closure members form 'an'en'closed dead air space withinsaid closure.

References Cited in the file of thispatent UNITED STATES PATENTS

